The series dates to 1903, and Oregon State has a 187-162 edge over the Ducks, who have won seven of the past nine games between the schools.
Tres Tinkle had 19 points, 12 rebounds and five assists as Oregon State took control of the game in the second half to beat archrival Oregon 76-64 on Friday night.
Oregon State and Oregon next travel to Arizona next week for games against the Sun Devils and Wildcats.
Neither Oregon nor host Oregon State had a spurt long enough or strong enough to create separation. (16 points, six assists) and Drew Eubanks (15 points, eight rebounds, two blocks) delivered, and so did Seth Berger, a graduate transfer from UMass who notched a season-high 12 points.
Oregon State sits at 10-5 on the season, already doubling last year's abysmal win total, and the Beavs are just getting things started. Tinkle only had four points in the first half but exploded for 15 points in the second half, and he finished the night with 19 points, 12 rebounds, and four assists.
Paul White had 16 points and six rebounds for OR (11-5, 1-2), which was limited to 36.2 percent (25 of 69), its second-lowest shooting percentage of the season. Harris is averaging 3.8 points and a team-high 3.1 assists in 13.9 minutes per game.
"We just came out and played a lot tougher in the second half", he said. Oregon State averages 75.2 points per game on offense while allowing 68.9 per game on defense.
The Beavers surged ahead 45-38 after a 9-2 run, capped by a Thompson 3-pointer with 12:44 left. Coach Tinkle urged his team not to relax, knowing the offense OR could quickly produce.
That momentum didn't last long as the Ducks came back with five quick points. The Ducks are 11-4 overall, 1-1 in the Pac-12 and 6-8 against the spread. Kendal Manuel hit a big 3-pointer after a Beavers' offensive rebound. He finished with nine points and five rebounds in 20 minutes off the bench.
Another intriguing piece is Steven Thompson Jr.'s younger brother Ethan Thompson, a freshman guard who has started every game thus far. Payton Pritchard is leading OR with 15.4 points and 4.3 assists per game while Troy Brown is adding 12.7 points and 7.6 rebounds per contest.
"We challenged our guys at halftime to pick up the intensity and get more aggressive", Tinkle said.
OR averaged 37.4 percent on 3-pointers but was 8 of 29 (27.6) Friday.
Oregon State: Thompson Jr. became the 40th Oregon State player to join the 1,000 point club. Having a healthy Tres Tinkle back - he missed the final 26 games last season with a broken right wrist - has provided a major boost. The Ducks made their last two shots before halftime to cut the Beavers' lead to one.